From f4190c2f12527e37304f7c185afa0449fa9dee1c Mon Sep 17 00:00:00 2001 From: Dan Williams Date: Tue, 6 Jul 2010 12:48:56 -0700 Subject: mdmon: satisfy glibc tls abi requirements with pthreads Setting up a proper tls descriptor is required to conform to the abi [1]. Until it can be implemented in mdmon use pthreads instead of clone(2) to let glibc handle the details. The old behaviour can be had by un-defining USE_PTHREADS. Note, the "O2" builds need LDFLAGS now to pick up the '-pthread' option. [1]: http://people.redhat.com/drepper/tls.pdf Signed-off-by: Dan Williams --- Makefile | 14 +++++++++++--- mdmon.c | 42 +++++++++++++++++++++++++++++++++++++++--- 2 files changed, 50 insertions(+), 6 deletions(-) diff --git a/Makefile b/Makefile index 237f4fc..0f42f88 100644 --- a/Makefile +++ b/Makefile @@ -75,6 +75,14 @@ ALTFLAGS = -DALT_RUN=\"$(ALT_RUN)\" -DALT_MAPFILE=\"$(ALT_MAPFILE)\" VARFLAGS = -DVAR_RUN=\"$(VAR_RUN)\" CFLAGS = $(CWFLAGS) $(CXFLAGS) -DSendmail=\""$(MAILCMD)"\" $(CONFFILEFLAGS) $(ALTFLAGS) $(VARFLAGS) +# The glibc TLS ABI requires applications that call clone(2) to set up +# TLS data structures, use pthreads until mdmon implements this support +USE_PTHREADS = 1 +ifdef USE_PTHREADS +CFLAGS += -DUSE_PTHREADS +LDFLAGS += -pthread +endif + # If you want a static binary, you might uncomment these # LDFLAGS = -static # STRIP = -s @@ -149,13 +157,13 @@ mdadm.klibc : $(SRCS) mdadm.h $(CC) -nostdinc -iwithprefix include -I$(KLIBC)/klibc/include -I$(KLIBC)/linux/include -I$(KLIBC)/klibc/arch/i386/include -I$(KLIBC)/klibc/include/bits32 $(CFLAGS) $(SRCS) mdadm.Os : $(SRCS) mdadm.h - $(CC) -o mdadm.Os $(CFLAGS) -DHAVE_STDINT_H -Os $(SRCS) + $(CC) -o mdadm.Os $(CFLAGS) $(LDFLAGS) -DHAVE_STDINT_H -Os $(SRCS) mdadm.O2 : $(SRCS) mdadm.h mdmon.O2 - $(CC) -o mdadm.O2 $(CFLAGS) -DHAVE_STDINT_H -O2 -D_FORTIFY_SOURCE=2 $(SRCS) + $(CC) -o mdadm.O2 $(CFLAGS) $(LDFLAGS) -DHAVE_STDINT_H -O2 -D_FORTIFY_SOURCE=2 $(SRCS) mdmon.O2 : $(MON_SRCS) mdadm.h mdmon.h - $(CC) -o mdmon.O2 $(CFLAGS) -DHAVE_STDINT_H -O2 -D_FORTIFY_SOURCE=2 $(MON_SRCS) + $(CC) -o mdmon.O2 $(CFLAGS) $(LDFLAGS) -DHAVE_STDINT_H -O2 -D_FORTIFY_SOURCE=2 $(MON_SRCS) # use '-z now' to guarantee no dynamic linker interactions with the monitor thread mdmon : $(MON_OBJS) diff --git a/mdmon.c b/mdmon.c index 0c37426..c4c0181 100644 --- a/mdmon.c +++ b/mdmon.c @@ -58,8 +58,11 @@ #include #include #include - +#ifdef USE_PTHREADS +#include +#else #include +#endif #include "mdadm.h" #include "mdmon.h" @@ -71,7 +74,39 @@ int mon_tid, mgr_tid; int sigterm; -int run_child(void *v) +#ifdef USE_PTHREADS +static void *run_child(void *v) +{ + struct supertype *c = v; + + mon_tid = syscall(SYS_gettid); + do_monitor(c); + return 0; +} + +static int clone_monitor(struct supertype *container) +{ + pthread_attr_t attr; + pthread_t thread; + int rc; + + mon_tid = -1; + pthread_attr_init(&attr); + pthread_attr_setstacksize(&attr, 4096); + pthread_attr_setdetachstate(&attr, PTHREAD_CREATE_DETACHED); + rc = pthread_create(&thread, &attr, run_child, container); + if (rc) + return rc; + while (mon_tid == -1) + usleep(10); + pthread_attr_destroy(&attr); + + mgr_tid = syscall(SYS_gettid); + + return mon_tid; +} +#else /* USE_PTHREADS */ +static int run_child(void *v) { struct supertype *c = v; @@ -85,7 +120,7 @@ int __clone2(int (*fn)(void *), int flags, void *arg, ... /* pid_t *pid, struct user_desc *tls, pid_t *ctid */ ); #endif - int clone_monitor(struct supertype *container) +static int clone_monitor(struct supertype *container) { static char stack[4096]; @@ -103,6 +138,7 @@ int __clone2(int (*fn)(void *), return mon_tid; } +#endif /* USE_PTHREADS */ static int make_pidfile(char *devname) { -- cgit